Proximity sensors for sensing proximity of a sense target such as a human body include the following type as known. The proximity sensor comprises a bottomed cylindrical fixed shield electrode, a disc-like detection substrate attached to the opening end of the fixed shield electrode, and a sensor electrode arranged at the central portion of the detection substrate to face a sense target.
The proximity sensor also comprises a movable shield electrode arranged outside the fixed shield electrode and slidable along the axial direction. Thus, it is configured with these members to adjust the sensible range and sensibility in accordance with various detection conditions and sense the sense target reliably (see, for example, Patent Document 1).
The proximity sensor may be given directivity in this way with arrangement of the shield electrode on the circumference or the rear of the sensor electrode to form a dead zone, thereby determining the range of the sense region within certain directions from the sensor electrode in general.    Patent Document 1: JP 2001-35327A